Handheld computer system that attempts to establish an alternative network link upon failing to establish a requested network link

ABSTRACT

A computer system that attempts to establish an alternative network link upon failing to establish a requested network link is described. The computer system may encounter conditions where access to numerous networks, in particular wireless networks, is not available. Rather than only providing an error message to the user upon a failed attempt to establish the requested network link, the computer system determines whether the user has designated an alternative network link in case the requested network link cannot be established, whereas the alternative network link is selected from the plurality of network links that the computer system is configured to support. If an alternative network link has been designated, the computer system attempts to establish the alternative network link. Hence, the user experience is made smooth and uneventful when the requested network link cannot be established.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of application Ser. No.09/847,720, entitled “HANDHELD COMPUTER SYSTEM THAT ATTEMPTS TOESTABLISH AN ALTERNATIVE NETWORK LINK UPON FAILING TO ESTABLISH AREQUESTED NETWORK LINK,” filed May 1, 2001, and assigned to the assigneeof the present application. The subject matter in the above-identifiedco-pending and commonly owned application(s) is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to the field of computersystems. More particularly, the present invention relates to the fieldof network functionality that attempts to establish a requested networklink or, if necessary, attempts to establish any other alternativenetwork link that a user has previously designated for the requestednetwork link.

2. Related Art

Computers and other electronic systems or devices (e.g., personaldigital assistants) have become integral tools used in a wide variety ofdifferent applications, such as in finance and commercial transactions,computer-aided design and manufacturing, health care, telecommunication,education, etc. Computers along with other electronic devices arefinding new applications as a result of advances in hardware technologyand rapid development in software technology. Furthermore, thefunctionality of a computer system or other type of electronic system ordevice is dramatically enhanced by coupling these stand-alone devicestogether in order to form a networking environment. Within a networkingenvironment, users may readily exchange files, share information storedon a common database, pool resources, and communicate via electronicmail (e-mail) and via video teleconferencing. Furthermore, computers orother types of electronic devices which are coupled to the Internetprovide their users access to data and information from all over theworld.

The functionality of an electronic system (e.g., a palmtop computersystem, a desktop computer system, a cellular phone, a pager, etc.) isenhanced by including an electronic display device. On occasion, theelectronic system includes one or more communication ports forexchanging or sharing data with other electronic systems or with anetwork. For example, an infrared (IR) communication port, a RF (radiofrequency) communication port, or other type of communication port canbe incorporated into the electronic system. A communication port ispositioned in the electronic system according to a variety of factors,such as space requirements, industry standards, and convenience to auser.

A personal digital assistant (commonly referred to as a PDA) is apalmtop computer system. It is appreciated that the personal digitalassistant is a portable handheld device that is used as an electronicorganizer which has the capability to store a wide range of informationthat includes daily appointments, numerous telephone numbers of businessand personal acquaintances, and various other information. Moreover, thepersonal digital assistant can also access information from theInternet, as mentioned above. In particular, the personal digitalassistant can browse Web pages located on the Internet. Typically, thepersonal digital assistant includes an electronic display device havinga display area (e.g., a screen) that is smaller in size relative to adisplay area associated with a standard-sized electronic display device(e.g., 15 inch monitor, 17 inch monitor, etc.) which is part of adesktop computer system or a laptop computer system.

Typically, the personal digital assistant includes one or morecommunication ports (e.g., an IR communication port, a RF (radiofrequency) communication port, a serial communication port, an Ethernetcommunication port, a cellular phone communication port, etc.). Forexample, a IR communication port is positioned along the top edge of thepersonal digital assistant so that a user can conveniently view and readthe electronic display device and at the same time communicate withanother electronic system located across from the user while the userholds the personal digital assistant.

Moreover, the network capability of the personal digital assistantenhances a user's experience, As new network technologies emerge,additional network functionality is incorporated into the personaldigital assistant. For example, a variety of wireless networks are beingdeployed to serve a wide range of devices including a personal digitalassistant. Having access to many different types of networks improvesthe productivity of the user and increases demand for the personaldigital assistant. However, the personal digital assistant may notalways be able to establish a network link with some of these emergingnetworks because of numerous reasons. Some of these reasons include:insufficient network capacity, technical network difficulties, and slowrollout of the coverage area of the emerging networks.

Typically, if the personal digital assistant fails to establish arequested network link, the user has to reconfigure the networkfunctionality of the personal digital assistant so that, on a subsequentattempt to establish a network link, another type of network link isattempted. If the personal digital assistant fails again to establishthe requested network link, the user again has to reconfigure thenetwork functionality of the personal digital assistant so that, onanother attempt to establish a network link, yet another type of networklink is attempted. Such intervention by the user degrades the userexperience and increases user frustration. Moreover, the situation canonly get worse in the future with the continual development of morenetwork technologies.

SUMMARY OF THE INVENTION

A computer system that attempts to establish an alternative network linkupon failing to establish a requested network link is described. Thecomputer system may encounter conditions where access to numerousnetworks, in particular wireless networks, is not available. Rather thanonly providing an error message to the user upon a failed attempt toestablish the requested network link, the computer system determineswhether the user has designated an alternative network link in case therequested network link cannot be established, whereas the alternativenetwork link is selected from the plurality of network links that thecomputer system is configured to support. If an alternative network linkhas been designated, the computer system attempts to establish thealternative network link. Hence, the user experience is made smooth anduneventful when the requested network link cannot be established.

In a chain implementation, the user designates one or severalalternative network links for a particular network link. Upon failure toestablish the particular network link, the computer system sequentiallyattempts to establish one of the alternative network links. The user haswide flexibility. For example, the user can omit providing analternative network link for some of the network links supported by thecomputer system. Moreover, the user can designate any number ofalternative network links for any of the network links supported by thecomputer system.

In a loop implementation, the user designates one or several alternativenetwork links for a particular network link. The computer systemattempts the particular network link and then, if the particular networklink cannot be established, attempts to establish the alternativenetwork link(s). If no network link was established, the computer systemagain attempts to establish the particular network link and, ifnecessary, again attempts to establish the alternative network link(s).The computer system can continue this loop until a network link isestablished or until the user decides to stop the loop.

These and other advantages of the present invention will no doubt becomeapparent to those of ordinary skill in the art after having read thefollowing detailed description of the preferred embodiments which areillustrated in the drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthis specification, illustrate embodiments of the invention and,together with the description, serve to explain the principle of thepresent invention.

FIG. 1 illustrates a block diagram of a first exemplary networkenvironment including a personal digital assistant on which the presentinvention can be practiced.

FIG. 2A illustrates a block diagram of a second exemplary networkenvironment including a personal digital assistant on which the presentinvention can be practiced, whereas the personal digital assistant iscoupled to other computer systems and the Internet via a cradle device.

FIG. 2B illustrates a block diagram of a third exemplary networkenvironment including a personal digital assistant on which the presentinvention can be practiced, whereas the personal digital assistant iscoupled to other computer systems and the Internet via a network port.

FIG. 3 illustrates a top side perspective view of a personal digitalassistant on which the present invention can be practiced.

FIG. 4 illustrates a bottom side perspective view of the personaldigital assistant of FIG. 3.

FIG. 5 illustrates a perspective view of another personal digitalassistant on which the present invention can be practiced.

FIG. 6 illustrates a logical circuit block diagram of a personal digitalassistant on which the present invention can be practiced.

FIG. 7 illustrates a perspective view of a cradle device for connectingthe personal digital assistant to other systems via a communicationinterface.

FIG. 8 illustrates a software environment on which the present inventioncan be practiced.

FIG. 9 illustrates a plurality of network links each having analternative network link designation in accordance with an embodiment ofthe present invention.

FIG. 10 illustrates a first plurality of network links each having analternative network link designation and a second plurality of networklinks each having an alternative network link designation in accordancewith an embodiment of the present invention.

FIG. 11 illustrates operation of a first loop implementation forattempting multiple network links in accordance with an embodiment ofthe present invention.

FIG. 12 illustrates operation of a second loop implementation forattempting multiple network links in accordance with an embodiment ofthe present invention.

FIG. 13 illustrates a message displayed to a user in accordance with anembodiment of the present invention.

FIG. 14 illustrates a flow chart showing a method of enabling a user toprovide the alternative network link designations for the network linkssupported by a personal digital assistant in accordance with anembodiment of the present invention.

FIG. 15 illustrates a flow chart showing a method of establishing anetwork link on a personal digital assistant in accordance with anembodiment of the present invention.

The drawings referred to in this description should not be understood asbeing drawn to scale except if specifically noted.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. While the invention will be described in conjunction with thepreferred embodiments, it will be understood that they are not intendedto limit the invention to these embodiments. On the contrary, theinvention is intended to cover alternatives, modifications andequivalents, which may be included within the spirit and scope of theinvention as defined by the appended claims. Furthermore, in thefollowing detailed description of the present invention, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. However, it will be recognizedby one of ordinary skill in the art that the present invention may bepracticed without these specific details. In other instances, well knownmethods, procedures, components, and circuits have not been described indetail as not to unnecessarily obscure aspects of the present invention.

Although the description of the present invention will focus on apersonal digital assistant or handheld computer system, the presentinvention can be practiced on other types of computer systems.

Computer System Environment

One of the common types of computer systems which can be used topractice the present invention is referred to as a personal digitalassistant, or commonly called a PDA. The personal digital assistant is apocket sized electronic organizer with the capability to store telephonenumbers, addresses, daily appointments, and software that keeps track ofbusiness or personal data such as expenses, etc. Furthermore, thepersonal digital assistant also has the ability to connect to a personalcomputer, enabling the two devices to exchange updated information.Additionally, the personal digital assistant can also be connected to' amodem, enabling it to have electronic mail (e-mail) capabilities overthe Internet along with other Internet capabilities. Alternatively, thepersonal digital assistant can have a network port (e.g., an EthernetLocal Area Network (LAN) port) to access a network coupled to theInternet, enabling the personal digital assistant to have electronicmail (e-mail) capabilities over the Internet along with other internetcapabilities. Moreover, an advanced personal digital assistant can haveInternet capabilities over a wireless communication interface (e.g.,radio interface). In particular, the personal digital assistant can beused to browse Web pages located on the Internet. The personal digitalassistant can be coupled to a networking environment. It should beappreciated that embodiments of the present 15 invention are well suitedto operate within a wide variety of computer systems, some of which canbe communicatively coupled to a networking environment.

FIG. 1 is a block diagram of a first exemplary network environment 50including a personal digital assistant 100 on which the presentinvention can be practiced. The personal digital assistant 100 is alsoknown as a palmtop or palm-sized electronic system or computer system.Here, the personal digital assistant 100 has the ability to transmit andreceive data and information over a wireless communication interface(e.g., a radio interface). The personal digital assistant 100 is oneexemplary computer system on which the present invention can operate.The present invention can operate on any other type of computer system.

In one embodiment, base station 32 is both a transmitter and receiverbase station which can be implemented by coupling it into an existingpublic telephone network 34. Implemented in this manner, base station 32enables the personal digital assistant 100 to communicate with a proxyserver computer system 36, which is coupled by wire 35 to the existingpublic telephone network 34. Alternatively, a private telephony system,a private data network, or any other communication network can beimplemented as alternatives for the existing public telephone network 34Furthermore, proxy server computer system 36 is coupled to the Internet52, thereby enabling the personal digital assistant 100 to communicatewith the Internet 52. Alternatively, a router, a switch, or any otherinterface device can be implemented as alternatives for the proxy servercomputer system 36. It should be appreciated that within the presentembodiment, one of the functions of proxy server 36 is to performoperations over the Internet 52 on behalf of the personal digitalassistant 100. For example, proxy server 36 has a particular Internetaddress and acts as a proxy device for the personal digital assistant100 over the Internet 52. It should be further appreciated that othercommunications networks may be utilized in practicing the presentinvention.

The data and information which are communicated between base station 32and the personal digital assistant 100 are a type of information anddata that can conventionally be transferred and received over a publictelephone wire network system. However, a wireless communicationinterface is utilized to communicate data and information between thepersonal digital assistant 100 and base station 32. It should beappreciated that one embodiment of a wireless communication system inaccordance with the present invention is the Mobitex wirelesscommunication system.

FIG. 2A illustrates a block diagram of a second exemplary networkenvironment 51A including a personal digital assistant 100 on which thepresent invention can be practiced, whereas the personal digitalassistant 100 is coupled to other computer systems and the Internet viaa cradle device. Network system 51A comprises a host computer system 56which can either be a desktop computer system as shown, or,alternatively, can be a laptop computer system 58. Optionally, more thanone host computer system 56 can be used within network system 51A. Hostcomputer systems 58 and 56 are shown connected to a communication bus54, which in one embodiment can be a serial communication bus, but couldbe of any of a number of well known designs (e.g., a parallel bus,Ethernet Local Area Network (LAN), etc.). Optionally, bus 54 can providecommunication with the Internet 52 using a number of well knownprotocols.

Importantly, bus 54 is also coupled to a cradle 60 for receiving andinitiating communication with the personal digital assistant 100. Cradle60 provides an electrical and mechanical communication interface betweenbus 54 (and any device coupled to bus 54) and the personal digitalassistant 100 for two-way communications. The personal digital assistant100 also contains a wireless infrared communication mechanism 64 forsending and receiving information from other devices.

FIG. 2B illustrates a block diagram of a third exemplary networkenvironment 51B including a personal digital assistant; 100 on which thepresent invention can be practiced, whereas the personal digitalassistant 100 is coupled to other computer systems 58 and 56 and theInternet 52 via a network port 55. As depicted in FIG. 2B, the personaldigital assistant 100 includes a network port 55 to couple to acommunication bus 54, whereas the desktop computer system 56 and thelaptop computer system, as well as the Internet 52, can be coupled tothe communication bus 54. The communication bus 54 can be implemented inany format, such as an Ethernet Local Area Network (LAN).

With reference to FIGS. 1, 2A, and 2B, it is appreciated that thepersonal digital assistant 100 can be used in a network environmentcombining elements of networks 50, 51A, and 51B. That is, the personaldigital assistant 100 can include a wireless infrared communicationmechanism, a signal (e.g., radio) receiver/transmitter device, and anetwork port.

FIG. 3 is a perspective illustration of the top face 100 a of oneembodiment of the personal digital assistant or palmtop computer system100. The top face 100 a has a display screen 105 surrounded by a bezelor cover. A removable stylus 80 is also shown. The display screen 105 isa touch screen able to register contact between the screen and the tipof the stylus 80. The stylus 80 can be of any material to make contactwith the display screen 105. The top face 100 a also has one or morededicated and/or programmable buttons 75 for selecting information andcausing the computer system to implement functions. The an/off button 95is also shown. Moreover, a user is able to control specificfunctionality of the personal digital assistant 100 by using itsplurality of buttons 75 (e.g., to invoke telephone/address data,calendar data, to-do-list data, memo pad data, etc.). Furthermore, theuser can utilize the stylus 80 in conjunction with the display screen105 in order to cause the personal digital assistant 100 to perform amultitude of different functions. One such function is the selecting ofdifferent functional operations of the personal digital assistant 100,which are accomplished by touching stylus 80 to specific areas ofdisplay screen 105. Another such function is the entering of data intothe exemplary personal digital assistant 100.

FIG. 3 also illustrates a handwriting recognition pad 106 or “digitizer”containing two regions 106 a and 106 b. Region 106 a is for the drawingof alphabetic characters therein for automatic recognition, and region106 b is for the drawing of numeric characters therein for automaticrecognition. The stylus 80 is used for stroking a character within oneof the regions 106 a and 106 b. The stroke information is then fed to aninternal processor for automatic character recognition. Once charactersare recognized, they are typically displayed on the screen 105 forverification and/or modification.

FIG. 4 illustrates the bottom side 100 b of one embodiment of thepersonal digital assistant or palmtop computer system 100 that can beused in accordance with various embodiments of the present invention. Anextendible antenna 85 is shown, and also a battery storage compartmentdoor 90 is shown. The antenna 85 enables the personal digital assistant100 to be communicatively coupled to a network environment (as shown inFIG. 1) thereby enabling a user to communicate information with otherelectronic systems and electronic devices coupled to the network. Acommunication interface 180 is also shown. In one embodiment of thepresent invention, the communication interface 180 is a serialcommunication port, but could also alternatively be of any of a numberof well-known communication standards and protocols (e.g., parallel,SCSI (small computer system interface), Firewire (IEEE 1394), Ethernet,etc.).

FIG. 5 illustrates a perspective view of another personal digitalassistant 100 on which the present invention can be practiced. Here, thepersonal digital assistant 100 includes a display screen 105 and ahandwriting recognition pad 106 or “digitizer, as well one or morededicated and/or programmable buttons 75 for selecting information andcausing the personal digital assistant 100 to implement particularfunctions. It should be understood that the present invention can bepracticed on personal digital assistants having other configurations anddesigns.

Referring now to FIG. 6, portions of the personal digital assistant 100are comprised of computer-readable and computer-executable instructionswhich reside, for example, in computer-readable media of the personaldigital assistant 100.

FIG. 6 is a block diagram of interior components of a personal digitalassistant 100 on which the present invention can be practiced. Thepersonal digital assistant 100 includes an address/data bus 110 forcommunicating information, a central processor 101 coupled to the bus110 for processing information and instructions, a volatile memory 102(e.g., random access memory, static RAM, dynamic RAM, etc ) coupled tothe bus 110 for storing information and instructions for the centralprocessor 101 and a non-volatile memory 103 (e.g., read only memory,programmable ROM, flash memory, EPROM, EEPROM, etc.) coupled to the bus110 for storing static information and instructions for the processor101. The personal digital assistant 100 also includes an optional datastorage device 104 (e.g., memory card, hard drive, etc.) coupled withthe bus 110 for storing information and instructions. Data storagedevice 104 can be removable. As described above, the personal digitalassistant 100 also includes an electronic display device 105 coupled tothe bus 110 for displaying information to the computer user. In oneembodiment, PC board 225 can include the processor 101, the bus 110, theROM 103 and the RAM 102.

With reference still to FIG. 6, the personal digital assistant 100 alsoincludes a signal transmitter/receiver device 108 which is coupled tobus 110 for providing a communication link between the personal digitalassistant 100 and a network environment (e.g., network environments 50and 51 of FIGS. 1 and 2, respectively). As such, signaltransmitter/receiver device 108 enables central processor unit 101 tocommunicate wirelessly with other electronic systems coupled to thenetwork. It should be appreciated that within the present embodiment,signal transmitter/receiver device 108 is coupled to antenna 85 (FIG. 5)and provides the functionality to transmit and receive information overa wireless communication interface. It should be further appreciatedthat the present embodiment of signal transmitter/receiver device 108 iswell-suited to be implemented in a wide variety of ways. For example,signal transmitter/receiver device 108 could be implemented as a modem.

In one embodiment, the personal digital assistant 100 includes acommunication circuit 109 coupled to bus 110. Communication circuit 109includes an optional digital signal processor (DSP) 120 for processingdata to be transmitted or data that are received via signaltransmitter/receiver device 108. Alternatively, some or all of thefunctions performed by DSP 120 can be performed by processor 101.

Also included in the personal digital assistant 100 of FIG. 6 is anoptional alphanumeric input device 106 which in one implementation is ahandwriting recognition pad 106 (“digitizer”) having regions 106 a and106 b (FIG. 3), for instance. Alphanumeric input device 106 cancommunicate information and command selections to processor 101. Thepersonal digital assistant 100 also includes an optional cursor controlor directing device (on-screen cursor control 107) coupled to bus 110for communicating user input information and command selections toprocessor 101. In one implementation, on-screen cursor control device107 is a touch screen device incorporated with display device 105.On-screen cursor control device 107 is capable of registering a positionon display device 105 where the stylus makes contact. The display device105 utilized with the personal digital assistant 100 may be a liquidcrystal display device, a cathode ray tube (CRT), a field emissiondisplay device (also called a flat panel CRT) or other display devicesuitable for generating graphic images and alphanumeric charactersrecognizable to the user. In the preferred embodiment, display device105 is a flat panel display.

FIG. 7 is a perspective illustration of one embodiment of the cradle 60for receiving the personal digital assistant or palmtop computer system100. Cradle 60 includes a mechanical and electrical interface 260 forinterfacing with communication interface 108 (FIG. 4) of the personaldigital assistant 100 when the personal digital assistant 100 is slidinto the cradle 60 in an upright position. Once inserted, button 270 canbe pressed to initiate two-way communication between the personaldigital assistant 100 and other computer systems or electronic devicescoupled to serial communication 265.

Attempting an Alternative Network Link upon Failure to Establish aRequested Network Link

Although the description of the present invention will focus on apersonal digital assistant or handheld computer system, the presentinvention can be practiced on other types of computer systems.

In an embodiment, the personal digital assistant 100 attempts toestablish an alternative network link upon failing to establish arequested network link. The personal digital assistant 100 may encounterconditions where access to numerous networks, in particular wirelessnetworks, is not available. Rather than only providing an error messageto the user upon a failed attempt to establish the requested networklink, the personal digital assistant 100 determines whether the user hasdesignated an alternative network link in case the requested networklink cannot be established, whereas the alternative network link isselected from the plurality of network links that the personal digitalassistant 100 is configured to support. If an alternative network linkhas been designated, the personal digital assistant 100 attempts toestablish the alternative network link. Therefore, the user experienceis made smooth and uneventful when the requested network link cannot beestablished. The present invention provides a simple manner to improvethe user experience and reduce interruptions which annoy and frustratethe user.

In an embodiment, the personal digital assistant 100 can be configuredto support a plurality of network links for communicating with numerousnetworks. These network links utilize a variety of network protocols andrequire a variety of physical connections (i.e., wired and wireless) toestablish communication with the numerous networks. Examples of networkprotocols include: PPP (Point-to-Point Protocol), Ethernet, GPRS(General Packet Radio Service), TCP/IP (Transmission ControlProtocol/Internet Protocol), Bluetooth wireless communication protocol,and IPX/SPX (Internetwork Packet Exchange/Sequenced Packet Exchange).Examples of physical connections include: wireless phone communication[e.g., GSM (Global System for Mobile Communications), CDMA (CodeDivision Multiple Access), TDMA (Time Division Multiple Access)], wiredphone communication, serial line communication, network cablecommunication, parallel line communication, and wireless communication.

As discussed above, numerous wireless networks are being deployedthroughout the country. The personal digital assistant 100 can beconfigured to support several of these wireless networks. However, thenumerous wireless networks may not be available in all regions of thecountry. The present invention enables the personal digital assistant100 to easily initiate an alternative network link (e.g., to a wirelessnetwork or a wired network) when the requested network link (e.g., to awireless network) cannot be established because any of a variety ofreasons, such as insufficient network capacity, technical networkdifficulties, and spotty network coverage.

FIG. 8 illustrates a software environment on which the present inventioncan be practiced. In an embodiment, the software environment of thepersonal digital assistant 100 includes an application layer 10, ashared library layer 20, and an operating system layer 30. This softwareenvironment provides the network functionality of the personal digitalassistant 100. Generally, an application 10 requests establishment of anetwork link (e.g., network link A 40, network link B 50, network link C60, or network link D 70) in response to an action by the user or anyother action. In particular, the application 10 sends a network openrequest (or makes a call) to a particular shared library 20 (e.g., anetwork library 20), whereas the shared library 20 is a code resourcedatabase which makes available a variety of API services thatapplications 10 can request. Specifically, the network library 20 makesavailable functions which perform network-related tasks, such as openinga network link, sending data via the network link, reading data from thenetwork link, etc.

In an embodiment, the network library 20 interfaces with the operatingsystem 30 to establish (or open) the requested network link (e.g.,network link A 40, network link B 50, network link C 60, or network linkD 70). If the network library 20 (which has network open code) fails toestablish the requested network link due to any of a variety of reasons(e.g., a network-related error, a time out error, a non-fatal operatingsystem error), the network library 20 subsequently attempts to establishan alternative network link which has been previously designated by theuser for the requested network link. It is possible for the user to omitdesignating the alternative network link. Moreover, the user candesignate multiple alternative network links in case the firstalternative network link cannot be established. Thus, the presentinvention gives the user a simple way to configure the personal digitalassistant 100 to try an alternative network link when his/her firstchoice of network link is not available. It should be understood thatthe present invention can be practiced in other types of softwareenvironments.

FIG. 9 illustrates a plurality of network links supported by a personaldigital assistant 100, each having an alternative network linkdesignation in accordance with an embodiment of the present invention.Here, the personal digital assistant 100 supports network link A 40(e.g., a wireless TCP/IP link), network link B 50 (e.g., a wired TCP/IPlink), network link C 60 (e.g., a Bluetooth wireless link), and networklink D 70 (e.g., wireless IPX/SPX link).

Moreover, FIG. 9 illustrates a chain implementation. In the chainimplementation, the user designates one or several alternative networklinks for a network link. In particular, the user selected network linkB, network link D, and network link C as the alternative network linkdesignation 40A for network link A 40. The user selected network link Cas the alternative network link designation 50A for network link B 50.Moreover, the user selected network link A, network link B, and networklink D as the alternative network link designation 60A for network linkC 60. In addition, the user selected network link C and network link Aas the alternative network link designation 70A for network link D 70.Upon failure to establish the network link, the personal digitalassistant 100 sequentially attempts to establish one of the alternativenetwork links.

For example, in the case where the requested network link is the networklink A, if the personal digital assistant 100 fails to establish thenetwork link A 40, the personal digital assistant 100 attempts toestablish the network link B 50 based on the order specified in thealternative network link designation 40A. Then, if the personal digitalassistant 100 fails to establish the network link B 50, the personaldigital assistant 100 attempts to establish the network link D 70 basedon the order specified in the alternative network link designation 40A.Moreover, if the personal digital assistant 100 fails to establish thenetwork link D 70, the personal digital assistant 100 attempts toestablish the network link C 60 based on the order specified in thealternative network link designation 40A. Thus, the user is able tochain together a list of alternative network links for the personaldigital assistant 100 to attempt in case the requested network linkcannot be established. It is possible to proceed in a loop by attemptingagain to establish the network link A 40 if the network link C 60 cannotbe established. The personal digital assistant 100 proceeds in a similarmanner in the case where the requested network link is the network linkB 50, the network link C 60, or the network link D 70.

The user has wide flexibility in creating the alternative network linkdesignations 40A, 50A, 60A, and 70A, as is evident in FIG. 9. Forexample, the user can omit providing an alternative network link forsome of the network links supported by the personal digital assistant100. Moreover, the user can designate any number of alternative networklinks for any of the network links supported by the personal digitalassistant 100. The alternative network link designations 40A, 50A, 60A,and 70A reflect choices made by the user based on the user's prioritiesand the network links supported by the personal digital assistant 100.It should be understood the present invention can be practiced withother number of network links.

FIG. 10 illustrates a first plurality of network links 140, 150, 160,and 170 supported by a personal digital assistant 100, each having analternative network link designation, and a second plurality of networklinks 240, 250, 260, and 270 supported by a personal digital assistant100, each having an alternative network link designation, in accordancewith an embodiment of the present invention.

Moreover, FIG. 10 illustrates a first loop implementation in the case ofthe first plurality of network links 140, 150, 160, and 170 supported bya personal digital assistant 100. In the first loop implementation, theuser designates an alternative network link for a network link. Thepersonal digital assistant 100 attempts to establish the network link(e.g., network link A 140, network link B 150, network link C 160, ornetwork link D 170) and then, if the network link cannot be established,attempts to establish the respective alternative network link (e.g.,alternative network link designation 140A, 150A, 160A, or 170A). If nonetwork link was established, the personal digital assistant 100 againattempts to establish the network link and, if necessary, again attemptsto establish the respective alternative network link. The personaldigital assistant 100 can continue this loop until any network link isestablished, until the user decides to stop the loop, until a predefinednumber of loop cycles have been performed, or until any other eventoccurs. Operation of the first loop implementation is depicted in FIG.11.

In addition, FIG. 10 illustrates a second loop implementation in thecase of the second plurality of network links 240, 250, 260, and 270supported by a personal digital assistant 100. In the second loopimplementation, the user creates a loop having several alternativenetwork links. The personal digital assistant 100 attempts the networklink (e.g., network link A 240, network link B 250, network link C 260,or network link D 270) and then, if the network link cannot beestablished, attempts to establish a respective alternative network link(e.g., alternative network link designation 240A, 250A, 260A, or 270A).If the respective alternative network link cannot be established, thepersonal digital assistant 100 proceeds to establish the particularalternative network link which is designated for the respectivealternative network link. The personal digital assistant 100 proceeds ina similar manner if the particular alternative network link cannot beestablished. Moreover, the personal digital assistant 100 can continuethis loop until any network link is established, until the user decidesto stop the loop, until a predefined number of loop cycles have beenperformed, or until any other event occurs. Operation of the second loopimplementation is depicted in FIG. 12.

FIG. 11 illustrates operation of a first loop implementation forattempting multiple network links in accordance with an embodiment ofthe present invention. For example, (as illustrated in table 200) in thecase where the requested network link is the network link A 140, if thepersonal digital assistant 100 fails to establish the network link A140, the personal digital assistant 100 attempts to establish thenetwork link B 150 based on the alternative network link designation140A.

In an embodiment, the personal digital assistant 100 provides a messageto the user before proceeding to attempt the network link B 150. FIG. 13illustrates a message 900 displayed to a user in accordance with anembodiment of the present invention. The message 900 informs the userthat the requested network link could not be established. In addition,the message 900 enables the user to control whether the personal digitalassistant 100 proceeds to the alternative network link. By selecting theoption 910, the user enables the personal digital assistant 100 toattempt to establish the alternative network link. By selecting theoption 920, the user stops the loop and prevents the personal digitalassistant 100 from attempting to establish the alternative network link.

Continuing, (as illustrated in table 300 and by arrow 10) if thepersonal digital assistant 100 fails to establish the network link B150, the personal digital assistant 100 attempts again to establish thenetwork link A 140 based on the alternative network link designation150A, since the network link A 140 is the respective alternative networklink for the network link B 150. The personal digital assistant 100 candisplay the message 900 (FIG. 13) before proceeding to attempt onceagain the network link A 140.

Moreover, (as illustrated in table 400 and by arrow 20) if the personaldigital assistant 100 fails to establish the network link A 140, thepersonal digital assistant 100 attempts again to establish the networklink B 150 based on the alternative network link designation 140A, sincethe network link B 150 is the respective alternative network link forthe network link A 140. The personal digital assistant 100 can displaythe message 900 (FIG. 13) before proceeding to attempt once again thenetwork link B 150. The first loop implementation can continue in amanner illustrated in tables 200, 300, and 400.

Moreover, the personal digital assistant 100 proceeds in a similarmanner in the case where the requested network link is the network linkB 150, the network link C 160, or the network link D 170.

FIG. 12 illustrates operation of a second loop implementation forattempting multiple network links in accordance with an embodiment ofthe present invention. For example, (as illustrated in table 500) in thecase where the requested network link is the network link A 240, if thepersonal digital assistant 100 fails to establish the network link A240, the personal digital assistant 100 attempts to establish thenetwork link C 260 based on the alternative network link designation240A.

In an embodiment, the personal digital assistant 100 provides a message900 (FIG. 13) to the user before proceeding to attempt the network linkC 260.

Continuing, (as illustrated in table 600 and by arrow 110) if thepersonal digital assistant 100 fails to establish the network link C260, the personal digital assistant 100 attempts to establish thenetwork link D 270 based on the alternative network link designation260A, since the network link D 270 is the respective alternative networklink for the network link C 260. The personal digital assistant 100 candisplay the message 900 (FIG. 13) before proceeding to attempt thenetwork link C 260.

Moreover, (as illustrated in table 700 and by arrow 120) if the personaldigital assistant 100 fails to establish the network link D 270, thepersonal digital assistant 100 attempts again to establish the networklink A 240 based on the alternative network link designation 270A, sincethe network link A 240 is the respective alternative network link forthe network link D 270. The personal digital assistant 100 can displaythe message 900 (FIG. 13) before proceeding to attempt once again thenetwork link A 240. The second loop implementation can continue in amanner illustrated in tables 500, 600, and 700.

Moreover, the personal digital assistant 100 proceeds in a similarmanner in the case where the requested network link is the network linkB 250, the network link C 260, or the network link D 270.

FIG. 14 illustrates a flow chart showing a method 1000 of enabling auser to provide the alternative network link designations for thenetwork links supported by a personal digital assistant 100 inaccordance with an embodiment of the present invention.

At step 1005, the method 100 in accordance with an embodiment of thepresent invention begins.

Continuing, at step 1010, each network link supported by the personaldigital assistant 100 is appropriately configured in the personaldigital assistant 100 so that the personal digital assistant 100 caninitiate and establish the network link when requested by an applicationor the user. For example, a network link set-up application can beinvoked to configure each network link. The network link set-up processincludes: identifying the type of network link, inputting networkprotocol values, and providing any other information (e.g., type ofmodem, number to be dialed by a wired or wireless modem, initializationstring, etc.) to enable the personal digital assistant 100 to initiateand establish the network link.

At step 1015, the user designates one or several alternative networklinks for a network link supported by the personal digital assistant100, whereas the alternative network link is selected from the pluralityof network links that the personal digital assistant 100 is configuredto support. Also, the user can specify whether the personal digitalassistant 100 proceeds as described with respect to FIG. 9 (i.e., chainimplementation), as described with respect to FIG. 11 (i.e., first loopimplementation), or as described with respect to FIG. 12 (i.e., secondloop implementation). The user can omit providing an alternative networklink for some of the network links supported by the personal digitalassistant 100. Moreover, the user can designate any number ofalternative network links for any of the network links supported by thepersonal digital assistant 100. Additionally, each network link and itscorresponding alternative network link designation are associated suchthat if the network link cannot be establish, the personal digitalassistant 100 attempts to establish another network link based on thealternative network link designation. In an embodiment, the alternativenetwork link designation is a user-defined preference property storedwith the configuration information of the corresponding network link.

At step 1020, the method 1000 ends.

FIG. 15 illustrates a flow chart showing a method 1200 of establishing anetwork link on a personal digital assistant 100 in accordance with anembodiment of the present invention. Reference is made to FIGS. 8-13.

At step 1205, the method 1200 in accordance with an embodiment of thepresent invention begins.

Continuing, at step 1210, an application on the personal digitalassistant 100 opens the network library (described with respect to FIG.8), whereas the network library has network open code that interfaceswith the operating system to initiate and establish a requested networklink.

Furthermore, at step 1215, the application sends a network open requestto the network library so that the requested network link is initiated.At step 1220, the network library receives the network open request.

At step 1225, the personal digital assistant 100 attempts to establishthe requested network link The personal digital assistant 100 initiatesthe requested network link by performing the network interface tasks(e.g., powering the modem, instructing the modem to dial a particularnumber, performing a handshake routine, etc.) that are required for therequested network link.

Moreover, at step 1230, the personal digital assistant 100 determineswhether an error message was generated due to any of a variety ofreasons (e.g., a network-related error, a time out error, a non-fataloperating system error), preventing the network link from beingestablished. If the error message was not generated, the personaldigital assistant 100 completes establishing the network link and themethod 1200 proceeds to step 1255.

Otherwise, the method 1200 proceeds to step 1235. At step 1235, thepersonal digital assistant 100 determines the appropriate alternativenetwork link designation based on the chain implementation, first loopimplementation, or second loop implementation. In an embodiment, thenetwork library receives the error message and determines thealternative network link designation corresponding to the network link.If the network link does not have an alternative network linkdesignation or if there is no additional alternative network link, themethod 1200 proceed to step 1255.

Otherwise, the method 1200 proceeds to step 1240. At step 1240, thepersonal digital assistant 100 informs the user that the requestednetwork link cannot be established and that another network link will beattempted based on the alternative network link designation. In anembodiment, the message 900 (FIG. 13) is displayed, allowing the user toprevent the personal digital assistant 100 from proceeding to thealternative network link. Alternatively, the personal digital assistant100 can proceed to the alternative network link without informing theuser that the requested network link could not be established.

At step 1245, the personal digital assistant 100 determines whether theuser desires the personal digital assistant 100 to continue to thealternative network link. If the user does not want the personal digitalassistant 100 to continue to the alternative network link, the methodproceeds to step 1255 and ends.

Otherwise, at step 1250, the personal digital assistant 100 attempts toestablish another network link based on the alternative network linkdesignation. The personal digital assistant 100 initiates the networklink by performing the network interface tasks (e.g., powering themodem, instructing the modem to dial a particular number, performing ahandshake routine, etc.) that are required for the network link. Themethod 1200 then proceeds to step 1230.

Those skilled in the art will recognize that portions of the presentinvention may be incorporated as computer instructions stored ascomputer program code on a computer-readable medium such as a magneticdisk, CD-ROM, and other media common in the art or that may yet bedeveloped.

Finally, aspects of the present invention can be implemented as anapplication, namely, a set of instructions (e.g., program code) whichmay, for example, be resident in the random access memory of a computersystem. Until required by the computer system, the set of instructionsmay be stored in another computer memory, for example, in a hard drive,or in a removable memory such as an optical disk (for eventual use in aCD-ROM) or floppy disk (for eventual use in a floppy disk drive), ordownloaded via the Internet or other computer network. In addition,although the various methods of the present invention described abovecan be conveniently implemented in a computer system selectivelyactivated or reconfigured by software, one of ordinary skill in the artwould also recognize that such methods of the present invention may becarried out in hardware, firmware, or in a more specialized apparatusconstructed to perform the required methods of the present invention.

The foregoing descriptions of specific embodiments of the presentinvention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteaching. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical application,to thereby enable others skilled in the art to best utilize theinvention and various embodiments with various modifications as aresuited to the particular use contemplated. It is intended that the scopeof the invention be defined by the Claims appended hereto and theirequivalents.

1. A method of enabling a user of an electronic system to provide analternative network link designation for network links supported by theelectronic system, comprising the steps of: a) configuring one of thenetwork links as network link so that the electronic system can initiateand establish it when requested by an application or the user; b)designating one or more alternative network link designations for theprimary network link, wherein said alternative network link designationsare selected from the network links supported by the electronic system;and c) storing the network link and the alternative network linkdesignations associated with the network link in the electronic system.2. A method of enabling a user of an electronic system to provide analternative network link designation for network links supported by theelectronic system, comprising the steps of: a) configuring one of thenetwork links as network link so that the electronic system can initiateand establish it when requested by an application or the user; b)designating one or more alternative network link designations for theprimary network link by omitting one or more network links from thenetwork links supported by the electronic system by the user; and c)storing one or more sets of the network link and the alternative networklink designations associated with the network link in the electronicsystem.